The monarch butterfly is one of the most iconic images in nature. Yet, the species is not as strong in number as many believe. In this week's "Issues of the Environment," WEMU's David Fair speaks to Nicole Muench, habitat and education coordinator for the National Wildlife Federation, about efforts to save the monarch butterfly from extinction.
* Both Ann Arbor and Ypsilanti have recently signed onto the Mayors’ Monarch Pledge, a program offered by NWF in which mayors pledge to enact specific actions in their communities that will enhance the value of the collective monarch butterfly habitat in their jurisdictions. I hope to have detailed info about the particulars of the pledges by tomorrow.
* The monarch needs protection due to several factors including the proliferation of Monsanto/Round-up-ready crops, deforestation in the wintering grounds, lack of milkweed host plants in the Midwest (tied to GMO crops), and the threat of severe weather which is more likely to become the norm as climate change progresses. Even a single severe weather event could be catastrophic if populations are low (A few years ago, a single early winter storm killed 10 times the number of monarchs that remain). The monarch population has declined 90% over the past 20 years, there are realistic fears that it may face eventual extinction, and a petition for listing as an endangered species was filed in 2014.
Mayors and other local government chief executives are taking action to help save the monarch butterfly, an iconic species whose populations have declined by 90% in the last 20 years. Through the National Wildlife Federation’s Mayors' Monarch Pledge, cities and municipalities are committing to create habitat and educate citizens about how they can make a difference at home. There are four steps to taking and implementing the pledge.
1. Take the Pledge - By taking the Mayors' Monarch Pledge, you are committing to both restore habitat in your community and encourage your citizens to do the same. Read the Mayors' Monarch Pledge and then take the pledge online! Both Ann Arbor Mayor Christopher Taylor and Ypsilanti Mayor Amanda Edmonds have signed the pledge.
2. Specify Your Actions - We will follow up with the point person specified in the online pledge form and work to identify at least 3 specific actions that your community will take in the next year. Mayors who decide to take 8 or more actions will receive special recognition and become a member of the Mayors' Monarch Pledge Leadership Circle. Once these specific actions have been identified, communities will report their progress through a simple online survey form. Read the Mayors' Monarch Pledge Action Items in English or Spanish, and then specify which actions you will take.
3. Take Action - Once you have taken the pledge and specified which actions your community will take over the next year, it’s time to start taking action! Over the next several months, NWF will be sharing best practices for cities and municipalities through our online resources section, occasional email updates, social media, and webinars. Please refer to our resources section for more details.
4. Report Progress - Once you have specified your actions and begun to take action we will ask communities to fill out a simple reporting form on a quarterly basis. The reporting process will only take about 5 minutes, and the data we collect will allow us to track the collective outcomes and impact of our work.
The factors contributing to this decline are many. The three lowest overwintering populations on record have been recorded in the last 10 years. This includes the all-time low of 0.67 hectares recorded [in 2010]. Three times (2002, 2004, 2010) in the last decade massive Pacific weather systems have moved into central Mexico in January and February. Each of these events resulted in heavy rain, often accompanied by hail, high winds, or freezing temperatures that devastated the monarch overwintering populations (for details see Status of the Population accounts in the Monarch Watch Blog). Mortality from these events ranged from 50 % (2010) to 80% (2002). Winter is the dry season in central Mexico and storms of this severity are an unusual and recent development. Illegal logging and a recent outbreak of bark beetles* continue to erode the integrity of the oyamel forests in which the monarchs overwinter. Many lines of research by Lincoln Brower and his colleagues have demonstrated the importance of maintaining the integrity of the forest canopy for successful overwintering by monarchs.
Loss of habitat in the summer breeding grounds is another factor that could be contributing to the decline in monarch numbers. We are losing 6,000 acres of potential monarch/pollinator habitat a day in the United Stated due to development (2.2 million acres per year). The losses of habitat due to the adoption of glyphosate tolerant corn and soybeans in the last 10 years amount to at least 100 million acres. The conversion of 7 million acres of Conservation Reserve Program (CRP) land to crops for the production of biofuels adds to the total. In all, we estimate the loss of habitat to be 147 million acres since Monarch Watch was started in 1992 – an area 4 times the state of Illinois. There is no doubt that our landscapes are becoming more fragmented and that there is less and less habitat for monarchs, pollinators and the wildlife that share the same habitat. This trend will surely continue…unless we step up and do something about it.
*Bark beetle outbreaks have been attributed to climate change in many forests in North America.
Then, on December 29, 2014, the US Fish & Wildlife Service announced it would conduct a year-long "status review." The agency will now collect data on monarch population trends, genetics, habitats, and existing conservation measures — all with an eye to determining how badly the butterflies' habitat is imperiled.
Tierra Curry of the Center for Biological Diversity (one of the groups that petitioned the agency in August) says these reviews don't happen often, so this is a big deal. "It's an acknowledgment of how dire the situation is," she said. Once the review is completed, the agency has three options: 1) It can decide that the butterflies are fine and say that endangered-species protections are "unwarranted." 2)It can list the monarch as a "threatened" or "endangered" species under the Endangered Species Act. 3) Or it can put the butterfly on a waiting list for protection (known as "warranted but precluded" — say, if the agency agrees that the monarchs are in trouble but lacks resources to act).
January 2016 - Two environmental groups filed a notice of intent to sue the U.S. Fish and Wildlife Service today over its failure to protect the monarch butterfly under the Endangered Species Act. The Center for Biological Diversity and Center for Food Safety petitioned for the monarch’s protection in August 2014, following a more than 80% decline in the butterfly’s population over the past two decades. In December 2014, the agency issued an initial positive decision on the petition and launched an official review of the butterfly’s status. The agency is now more than one year late in issuing a legally required “12-month finding” that will determine whether to protect the charismatic large and orange and black butterfly under the Act.
The groups’ lawsuit will force the agency to commit to a legally binding date to issue a final decision on the monarch’s protection. The “12-month finding” will either propose protection under the Endangered Species Act, reject protection under the Act, or add the butterfly to the candidate waiting list for protection.
The population has declined from a recorded high of approximately 1 billion butterflies in the mid-1990s to only 56.5 million butterflies last winter, the second lowest number ever recorded. The overall population shows a steep decline of 82% from the 20-year average. The population is expected to undergo a sizable rebound this winter due to favorable spring and summer weather, but monarchs need a very large population size to be resilient to threats from severe weather events. A single winter storm in 2002 killed an estimated 500 million monarchs — eight times the size of the entire current population. Severe weather is expected to take a toll on the population later this winter due to the strong El Niño this year.
Although the Fish and Wildlife Service has announced that it will provide a total of $3.2 million to support monarch conservation projects, that total falls far short of the funding that would be required by Endangered Species Act protection to restore enough monarch habitat to ensure the butterfly’s future. “The money the government has pledged sounds like a lot, but the truth is it isn’t even enough to restore 1 percent of the habitat that’s been lost,” said Curry. “We’re at risk of losing an animal that’s as American as apple pie, and nothing short of Endangered Species Act protection will guarantee that we save the monarch.”
“Despite the expected increase in the overwintering monarch population this year due to favorable weather, the monarch is still severely jeopardized by milkweed loss in its summer breeding grounds due to increasing herbicide use on genetically engineered crops,” said Kimbrell. “We will continue to do everything we can to ensure monarchs are protected under the Endangered Species Act.”
The butterfly’s dramatic decline has been driven in large part by the widespread planting of genetically engineered crops in the Midwest, where most monarchs are born. The vast majority of genetically engineered crops are made to be resistant to Monsanto’s Roundup herbicide, a potent killer of milkweed, the monarch caterpillar’s only food. The dramatic surge in Roundup use with Roundup Ready crops has virtually wiped out milkweed plants in midwestern corn and soybean fields. It is estimated that in the past 20 years these once-common, iconic orange-and-black butterflies may have lost more than 165 million acres of habitat — an area about the size of Texas — including nearly a third of their summer breeding grounds.
In addition to herbicide use with genetically engineered crops, monarchs are also threatened by global climate change, drought and heat waves, other pesticides, urban sprawl and logging on their Mexican wintering grounds. The Mexican government reported this month that 24 acres of the monarch’s key overwintering grounds were illegally logged this year.
What happens if the monarch gets protected?
If the monarch butterfly does get listed as threatened or endangered, any activity that gets federal funding or permitting and potentially harms monarch habitats would have to consult with the Fish & Wildlife Service to minimize the damage. Agriculture might be most heavily affected. The agency could, for instance, develop new guidance for farmers in the Midwest on how to protect milkweed, says Curry. (The guidance would likely exempt a lot of routine farming activities.) "With a lot of endangered species, it's difficult to address the causes," Curry says. "But that's not true of the monarch. We basically just need more milkweed." Some experts have suggested that farms could preserve milkweed if they avoided herbicide spraying around the edges of fields, for instance. "Don't spray along 100 feet along the edge of everyone's field, so that there's some native habitat left," Brower told me. But it's still not clear exactly what actions the agency might suggest.
Are GMOs responsible for the monarch's decline?
In recent years, some experts have blamed the decline of the monarch butterflies on the rise of new soy and corn crops that are genetically modified to be resistant to herbicides — such as Monsanto's Roundup. The idea is that this leads to heavier herbicide use, which in turn kills more milkweed.
But not everyone's convinced that herbicides are the sole reason for the decline of native plants near agricultural fields. Another recent study by scientists at the US Department of Agriculture and Penn State found that herbicide-tolerant native plants around farmland in Pennsylvania were declining at the same rate as less-tolerant plants. That suggests that other factors may be at work here. The Penn State researchers pointed out that farmers have made a lot of changes in recent decades apart from rising herbicide use — they've simplified their crop rotations, segregated crops and livestock, and employed new mechanical farming methods. What's more, woodlots, hedgerows, pastures, and wetlands have all been cleared to make way for bigger fields. So there may be more going on than just GMOs and herbicides.
In either case, there's broad agreement that milkweed plants are declining sharply throughout the Midwest. And that appears to be a major reason monarch butterflies are vanishing. Figuring out exactly why those plants are declining — and how best to protect them — is a crucial next step.
Some groups, like Monarch Watch, have encouraged people to plant more milkweed in their gardens and on other public and private lands. And Brower suggested in our interview that state highway departments could be more careful about mowing and spraying their highway medians (which often contain plenty of milkweed), particularly during the butterfly breeding season.
But these actions can only do so much. The University of Guelph study suggested that just 26% of milkweed loss since 1995 had occurred in public areas or parks. By contrast, 70% of the loss had occurred in "agricultural-intensive landscapes" — particularly in the south and central United States. So figuring out how to preserve undeveloped grasslands and bringing back milkweed plants seems to be the main task here.
An unusually cold, fierce winter storm in Mexico over a few days last March could mean seeing less of a once-regular summertime sight in Michigan — monarch butterflies. The storm hit around March 10 with snow, high winds, and freezing temperatures in some of the prime over-wintering grounds for the migrating monarchs, the high mountain oyamel fir forests in southern Mexico, places where they congregate in the tens of millions for winter. Monarchs are essentially tropical insects, but can tolerate cooler temperatures. However, they can freeze to death in sub-freezing temps over prolonged periods. "The mortality was really high; I would say in the millions," said David Mota-Sanchez, a Michigan State University entomologist who is helping research the impact of the winter storm on the butterflies.
That's a blow to an insect that is struggling to recover from historic population lows in recent years. The majestic monarch is the only butterfly known to make a two-way migration like birds, as it does every fall from its spring and summer grounds of Canada and the U.S. down to Mexico and parts of Central America. Many monarchs travel up to 4,000 miles every fall to their concentrated high-elevation over-winter location in Mexico where hundreds of millions hang in the oyamel fir forests that grow more than 7,800 feet up the mountainside.
The migration is multi-generational, with monarchs spending their winters in Mexico beginning to reproduce as temperatures rise and as they begin their northward trek. The first generation of offspring grows in Mexico and the southern U.S., and each successive generation of the butterflies moves farther north with the warmth. It takes three to four generations of Monarch butterflies to make it back to Michigan and Canada, where monarch eggs normally can be spotted in late May and through June on milkweed -- a wild plant named for the thick, milky liquid that flows within its broad, green leaves, and upon which the monarch is uniquely reliant.
Monarchs covered nearly 21 hectares of the Mexican over-winter grounds in the winter of 1996-97 and have averaged 6.4 hectares of coverage annually(A hectare is about 2.5 acres.). Their numbers dropped steadily in recent years, covering only 0.67 hectare in the winter of 2013-14. Those numbers were recovering, however, the past few winters, back up to 4 hectares this winter, Mota-Sanchez said. "We don't have all of the answers," Mota-Sanchez said. "There is a decline of milkweeds in the field, but there are other factors: parasites, weather conditions, predators." He said he is also studying the impact of pesticides used in farming on adult monarchs and their larvae.
Despite the winter storm losses, Mota-Sanchez says he's still confident the monarchs can recover over the multiple generations migrating north to a point where next winter's Mexican visitors are at least similar in numbers to the populations found this winter. In Michigan, Mota-Sanchez is using a U.S. Department of Agriculture grant to conduct outreach to farmers and citizens on the importance of restoring monarch habitats, and is working with others to grow milkweed in greenhouses to plant in the wild this spring. "So many scientists, so many teachers, so many people are concerned about the future of the monarch," he said. "For that reason, I am optimistic about the future."
How to help save the monarchs
Milkweed is an essential food plant for monarch butterflies in their egg-laying and larval stage — they don't much like other plants. Growing milkweed plants in backyards and elsewhere provides critical habitat the dwindling monarch butterfly populations. It's important to get only types of milkweed plants that are native to your area, and to not purchase plants or seeds with pesticides. For information on what types of milkweed plants are best to grow in Michigan, visit the Michigan State University Extension here.
For information on where to obtain native milkweed seeds, ask your local nursery or visit the Xerces Society's Milkweed Seed Finder site.